A retreaded tire that is manufactured by first attaching vulcanized tread rubber or unvulcanized tread material to a tire casing and then bonding by vulcanization has been proposed for a tire casing that has been used for a certain period of time and can be used repeatedly (for example, see JP2012-096762A (PTL 1)). By applying such techniques for retreaded tires, the casing can be used for an extended period of time, and the cost to the tire user can be effectively reduced.
A wide variety of treads can be used in tires, and treads can be selected from among a variety of thicknesses. Selecting a thin tread, for example, can reduce the rolling resistance coefficient, which greatly affects fuel consumption, yet the life of the tread shortens, thereby increasing retreading costs. Conversely, selecting a thick tread can lengthen the life of the tire and reduce retreading costs, yet the rolling resistance coefficient increases, causing fuel consumption to increase.
The tire user is thus unable to select an appropriate tread, and a tread that is still usable sometimes goes to waste.